How sorta cool stuff works: the Internet

Sean McKernan explains how the world’s easiest way to order pizza really works
Very few inventions have changed the world as much as the internet, especially in such a short space of time. Just fifty years old this year, the internet has changed from a scientific tool, into a mainstream provider of services used by 1.5 billion every day.

Before the internet, data could only be transferred between computers by manually entering it into the second computer. The modern internet evolved in the 1990s from no fewer than four other precursors first created in the 1960s.

The precursors of the internet came from various different sources: a model called Arpanet was designed to allow communication between universities; the RAND Corporation created a military computer network in the US; the National Physical Laboratory in England created a commercial computer network; and Cyclades was created by French researchers.

The internet is a network of over 350 million computers connected using various methods (wires, fibre optic cables, or satellites). Data is stored on large computers called servers throughout the world, and when needed is transferred to your computer using a set of rules called the TCP/IP protocol.

I obviously don’t want to bore you so I’ll spare you the details, but this protocol defines how data is transferred between computers. The data is initially split into thousands of small pieces, and is sent to your computer using different routes. It is then reassembled in your computer; this process is called packet switching.

Packet switching means that if one cable is severed, data can still flow using other routes. In 2008 a cable supplying the Middle East was destroyed but, using other cables the internet was still able to function fully.

The modern internet still relies heavily on cables hanging at 200m depth in the world’s oceans. Other methods of connection include satellites and radio waves.

To use the internet, each computer must be able to be identified and this is done using an IP address (four numbers unique to each computer on the internet) that function like your house address. Using this address data can be sent to your computer. When you type, say, www.google.com into your web browser, it is converted into the number which allows your computer to know where to go. (Google is 216.239.51.99 in case you wondered.)

One of the most important factors of the internet is speed, with broadband connections being some of the fastest. Broadband works by increasing the speed of the internet connection by using multiple ‘channels’ to increase the amount of data transferred.

To connect to the internet, most users will use an Internet Service Provider. These services act as a middleman between the internet and your computer. They are also able to restrict access to sites or files, such as file-sharing networks. This is a controversial practice, compared by some people to censorship. Eircom has recently been criticised for blocking access to the famous torrent site The Pirate Bay. Other governments place heavy censorship on the internet, such as China, which restricts access to many services and sites.

Many services now use the internet with banking, communication and gaming all heavily investing in their online systems. All of these useful services, and pizza deliveries, are now accessible from under your bed covers, making it increasingly difficult to get up for those early lectures – at least for me anyway…